gecko-dev/xpfe/browser/resources/content/navigator.css

/* ::::::::::
   :: Rules for 'hiding' portions of the chrome for special
   :: kinds of browser windows.
   ::::: */
 
window[chromehidden~="menubar"] .chromeclass-menubar {
  display: none;
}

window[chromehidden~="toolbar"] .chromeclass-toolbar {
  display: none;
}

window[chromehidden~="location"] .chromeclass-location {
  display: none;
}

window[chromehidden~="directories"] .chromeclass-directories {
  display: none;
}

window[chromehidden~="status"] .chromeclass-status {
  display: none;
}

window[chromehidden~="extrachrome"] .chromeclass-extrachrome {
  display: none;
}

/* ::::: urlbar autocomplete ::::: */

.autocomplete-result-popup[for="urlbar"] {
  -moz-binding: url("chrome://navigator/content/urlbarBindings.xml#autocomplete-result-popup") !important;
}

.autocomplete-result {
  -moz-binding: url("chrome://navigator/content/urlbarBindings.xml#autocomplete-result") !important;
}

.autocomplete-search-box {
  -moz-binding: url("chrome://navigator/content/urlbarBindings.xml#autocomplete-search-box");
}

.autocomplete-search-engine {
  -moz-binding: url("chrome://navigator/content/urlbarBindings.xml#autocomplete-search-engine");
}